Summary HDSS Core The Muzaffarpur HDSS is the only demographic surveillance site in the INDEPTH network that is located in an area endemic for VL was established in established in 2012 during the current NIH grant (1st August 2012 to 31st July 2017). Now it covers an area of 145sq km with 50 clusters ( geographically contiguous area) of Kanti block &16 villages from other blocks of district Muzaffarpur, Bihar. Last census was conducted in 2015. A total 111,999 from 16301 households were screened and information on current family size, new births and deaths, in/out migration, new cases of Kala-azar . All new 53 Kala-azar cases occurred since last survey (6th in 2013) was confirmed by document verification and rk39 test. It provides an excellent platform for conducting sentinel surveillance of the incidence of VL and PKDL at population level in the heartland of the VL epidemic in Bihar. We will investigate whether the declining trend in numbers of reported VL cases in Bihar State is also reflected in decreasing sero prevalence rates. All field based studies in all TMRC projects will be conducted through same plat form. The HDSS also offers the possibility of studying interaction of VL with other prevalent neglected topical diseases and effect of social and environmental factors known to be associated with VL. PKDL in itself is probably of low priority for the HDSS population but if screening for PKDL is combined with screening for other skin disorders followed by treatment of common treatable conditions, this would probably be very much welcomed. To further explore the apparent discrepancy between tuberculosis case notification figures for India and those for Bihar, the population based approach will allow us to identify all tuberculosis cases, also those treated by private practitioners and possibly not notified. In next TMRC it is decided that all information from the field ( including verbal autopsies) will be collected on tablets.